Okay so I got the suspension in the rear fixed, now all I did was have the heads and intake done by modern, the fastest the cars been is 10.54 last year the car was running 9.70s all day long. Now it’s all messed up, I put the timing at 34 degrees but I haven’t touch the carb .. how far up should I jet it? It’s a dog out of the hole 1.54 60 ft where last year I was running 1.28 - 1.30. So what kinda of jets should I go up too ? The car is really starting to get to me so before I through a forsale sign on it I’d thought I’d ask here for so suggestions thanks John

Look at your plugs.

Just because the heads are better doesn’t automatically mean you jet up. You may be to Rich now or issues with the carb from sitting

Haven’t had a run that made it the hole way ..

That was where I was heading. He thinks he's lean but he very well could be rich. The plugs would give a better idea which way to go.

If you had the engine all apart to have the heads re-worked than a bunch of stuff was touched. You could have a problem most anywhere. Could be a vacuum leak, or valve lash, or firing order is off or a few dozen other things.

I'd start with the basics and go from there. Confirm firing order, look at the plugs, check manifold vacuum while running, run a compression check, etc. Almost anything can go wrong when you pull and engine apart and put it back together. I think I've every mistake in the book and then I find another way to make one.

Checked all the easy thinkings. It’s just not running anywhere near what it should and I just can’t figure it out

What carb and what jets are in it now ?

Can you get or borrow and AFR guage?
Can you get to a chassis dyno to get help in trouble shooting and dialing the car up?
Is it blowing black smoke, a dog at idle/off idle.
Somehow i think you would know if its "that" rich.
Can you get someone to video a burn out and a run ?
What does engine vacuum look like at idle in neutral and i gear?

Are the plugs black and sooty or white as snow?

How long did your fuel sit?
Down here is "really, really" easy to have ones fuel turn to engine puke solution- wont run for squat.
Checked floats/fuel pressure?

Is distributer locked out or on a timing curve- if on a curve, make sure curve is still intact( nothing gave up in distributer)

we recently had an MSD issue, actually the connector between distributer and msd box- i check that all the time now- grin.

Sure hope you can find your gremlin.
How are water temps?
Any pressure in the cooling system after the runs?

I’d see about borrowing a known good carb off a somewhat similar combo.

Some guys laugh at me for never having an engine on a dyno in 44 years but having a RacePak in my car gives me info on every pass, not just in the dyno room.

Which spark box are you using?
The only thing i have ever had go bad that killed a ton of ET was a Digital 6 box. Took half a season to find the problem. Swapped it and car came back.
It would cause a miss in second and third gear was the symptom

agreed John
Dyno's still offer things a racepak cannot but a Racepak ( data gathering) offers us many things a dyno just cannot.
I do like the engine dyno for several reasons- one of course is that if we have any major issues we don't have to pull an engine.
The second for me is the repeatability that allows for testing/experimenting and that it doesn't put wear on the car.
But as soon as i can gather more data- I doubt i will ever use a chassis dyno again.
You have your chassis dyno every time you make a pass and with far more "real world" data than a chassis dyno can give.

If a brand new build car build and it was high hp, I would likely still hit a chassis dyno for a few pulls but, thats about the only reason i can think of if i had a Racepak.

* Jet for MPH.
* Squirters & pump cams for 60'

Be careful so one doesn't overlap the other. (i.e.: too much jet can mask a need for bigger squirters and/or a bigger (longer squirting) pump cam.

Smaller squirters will increase the duration of the squirt and bigger squirters will shorten the duration of a given pump cam. You don't want the squirt any longer or shorter than necessary because it will mess up the A/F ratio of the main metering system (jets).

Yep. All that stuff contributes to optimal ET’s. But his car is off 8 tenths or more.

John I have a good running 1050 Quickfuel I could let you use just to see if it changes at all.
I work in Kent not to far from you.

Gus

Gus I may take you up on that ..
here is a run done on the car

It’s now a 493
-1 ported heads from modern
Ported intake
1050 AED carb 95 primes and 96 second shooters I could tell you
11-1.1 comp
Crank trigger
Msd 6 al
Small roller 316-321 283 and 288 at 50 and .660- 663 4500-7200
Timing is set at 34
Checked wiring and all other small things.
This thing should be running 9.5 or better . Things a beast
In the Pitts and road but track not so much. I’m at a
Lost.

I have a 540 with B1s and a much larger cam then you .
1150 Carb and I have 93s in mine right now .

That’s what I’m getting at .. this thing should fall In the 9s ..
hell my 438 ran a best of 9.98 .. I might just put that back
In ..

I know you can’t compare carb to carb but my old high 9 oldschool (906 heads) build had 99 jets in my 1050 carb. My 8.50 build with 440-1 heads had 90-91’s Jets in the same carb